Firewalls

The purpose of a firewall is to either block or allow incoming traffic to a network by selectively restricting access to the network.

Traffic is controlled by monitoring the many network ports. A network port is an identified doorway. It has its own address. A network port is used for communicating between programs, other communication systems or the programs that frequently pass through hardware ports. Network ports are often numbered. A standard network will assign a port number to all of the data it sends out. The receiving side will guard its self until it understands which program, on its system, to send the data to. It does this by checking the attached port number. There are two ways a port ways a port may send/receive data:

1.       Simplex – data is sent/received in one direction at a time

2.       Duplex - data is sent/received simultaneously in both directions.

These software networks ports can also connect to internal programs on single computers.

                Users currently operating with firewalls are most likely to notice that when certain programs load on computers or when they are started, a warning message from the firewall may pop up, warning the user that there has been an attempt by the program to create an outbound connection. The firewall automatically configures legitimate programs to allow program up dates and other routine tasks.

                 When configuring a firewall, you must be careful as it is possible to block access to recourses that are required. This can cause programs to not work properly. There are some cases where too many restrictions have been placed in the firewall settings that the internet has been disabled.

                The best choice is to refer to a qualified technician or a reliable expert if you need help making choices about how much access a program is granted or denied.